This invention relates to the area of timepiece devices, and more particularly those which are capable of recording a voice or other audible signal for playback when an alarm set is triggered. Although such devices are already seen on the market today, and are described in U.S. Pat. No. 4,508,457 issued Apr. 2, 1985 to Aiawa and U.S. Pat. No. 4,717,261 issued Jan. 5, 1988 to Kita, et al., the present invention device disclosed herein represents an improvement over such prior art devices in that it uses microprocessor technology to control the setting and triggering of the alarm, as well as the signal digitizing of the audible signal, the addressing of the digitized signal into storage, and the processing of the digitized signal from storage and into an audible facsimile of the original input signal.
The use of a microprocessor to control such functions results in a variety of improvements over the individual logic components shown in the aforementioned patents. One advantage of using a microprocessor is the dependence of interrupts to check keypad and register status rather than the polling method as described in U.S. Pat. No. 4,717,261. The polling method is much more demanding of battery consumption, which is a consideration where the timekeeping apparatus involved is a travel alarm or wrist watch and the power source is a battery.
Another advantage to the use of a microprocessor is that the LCD (liquid crystal diode) driver/controller can be built into the microprocessor so that the LCD display can have an unlimited amount of flexibility as opposed to the methods described in the two aforementioned patents which are hardware devices and completely inflexible.
Moreover, because a microprocessor is used, a continuous power source is not required to maintain voice and memory data. This becomes a distinct advantage where the timekeeping apparatus is a travel alarm or wrist watch and the power source is a battery. Also, unlike the devices disclosed in the two aforementioned patents, external SRAM or DRAM memory is not required because the microprocessor contains ROM and the voice or audible sound may be stored in an analog EEPROM.
And finally, in the two aforementioned patents, because a microprocessor is not used, the hardware must be preset to specify a particular set of input/output rates of addressing analog signals into the memory, which results in limited predetermined record times. With the present invention, the input/output rate into the memory storage can be varied to suit the amount of memory present in the device so that appropriate record/playback times may be set.